Function: noun
Date: circa 1931
: a wave (as a sound wave) in which the particles of the medium vibrate in the direction of the line of advance of the wave
Function: noun
Date: circa 1931
: a wave (as a sound wave) in which the particles of the medium vibrate in the direction of the line of advance of the wave
Merriam Webster Collegiate English Dictionary. Merriam Webster - Энциклопедический словарь английского языка. 2012